Expression of proteins related to autotaxin–lysophosphatidate signaling in thyroid tumors

Abstract

Abstract Background We aimed to investigate the expression of proteins related with autotaxin (ATX)–lysophosphatidate (LPA) signaling and the clinical implications in primary and metastatic thyroid tumors. Methods We constructed tissue microarrays with 545 primary thyroid tumors [338 papillary thyroid carcinoma (PTC), 111 follicular carcinoma (FC), 69 medullary carcinoma (MC), 23 poorly differentiated carcinoma (PDC), and four anaplastic carcinoma (AC)]. Immunohistochemical stains for proteins related to ATX–LPA signaling (e.g., ATX, LPA1, LPA2, and LPA3) were performed. Results The expression of ATX was highest in MC, while the LPA1 expression was higher in PDC and AC, and the expression of LPA2 and LPA3 was highest in PTC (p < 0.001). Additionally, the expression of ATX, LPA1, and LPA2 was higher in conventional-type PTC than in follicular-variant PTC (p < 0.05). PTC with BRAF V600E mutation showed higher expression of ATX, LPA1, LPA2, and LPA3 than PTC without BRAF V600E mutation (p < 0.001). In univariate analysis, ATX positivity (p = 0.005) and LPA1 positivity (p = 0.014) were correlated with shorter overall survival in PTC. Conclusion Proteins related to the ATX–LPA axis showed different levels of expression in primary thyroid tumors according to subtype.

Keywords

• Autotaxin
• Lysophosphatidate
• Thyroid
• Tumor